This multi-disciplinary, implementation science project is nested within a larger NIH-funded study, the HIV-1 Counseling and Testing for Children at Home (CATCH) Study, which will examine uptake of, and response to, treatment in HIV-infected children identified via their parents. My sub-study will take place during the screening and enrollment phase for CATCH; we aim to develop and optimize operational mechanisms to identify undiagnosed, asymptomatic HIV-1 infected children in Kenya and bring them into HIV care. To find these undiagnosed children, we propose to access their HIV-1 infected parents through various access points at HIV testing and treatment centers and offer them either home-based or clinic-based testing for their children of unknown HIV status. Our intent is compare clinic- versus home-based testing-in terms of yield, acceptability, feasibility, and cost. In order to holistically understand the challenges and facilitators to identifying undiagnosed children through home-based or clinic-base testing, we will collect three types of data: traditional quantitative epidemiological and program data, qualitative data from parents and care providers, and cost and impact data. Through the combination of these three methods, we hope to translate the benefit of medical advances in the form of HIV testing and treatment to a currently underserved population of undiagnosed children through targeting implementation challenges.